Acetone Fixation and Embedding 339 



tinct and intense sections, but they were chiefly interested in fluores- 

 cence. So perhaps the best suggestion is to try all methods and dis- 

 cover which serves the particular investigation being imdertaken. 



Blank et al. {1951) use glycols if fixation is to be avoided, alcohol 

 or acetone if fixation is permissible. This method is as follows: 



procedure: 



1. Place slices (2-3 mm.) of tissue in cold propylene glycol in deep 

 freeze belo^v — 20°C: 1-2 hours. 



2. Transfer to mixture of carbowax, 55 °C: 2-3 hours. 



carbowax 4000 9 parts 



carbowax 1500 1 part 



3. Prepare blocks, page 81. 



4. Cut sections and float on slides according to Blank and McCarthy, 

 page 8 1 . 



5. Stain or tise for autoradiographs. Water-soluble substances ha\'e 

 not leached out. For autoradiographs, before each cut coat the 

 block face with thin molten wax. Press Avax-reinforced sections 

 against emulsion for exposure. See also: Freed (1933); Meryman 

 {19 '>9, I960); Woods and Pollister {1933). 



References: Blank et al. (1951); Feder (1958); Freed (1955); Gersh 

 (1932); Click and Malstrom (1952); Hancox (1957); Hoerr (1936); 

 Ibanez et al. (1960); Jennings (1951); Louis (1957); Mellors (1959); 

 Meryman (1959, 1960); Packer and Scott (1942); Patten and Brown 

 (1958); Simpson (1941); and Woods and Pollister (1955). 



Acetone Fixation and Embedding 



Gomori (1952) Method 



Chilled alcohol (95% or absolute) and acetone are used for preserva- 

 tion of tissues to be used for many kinds of enzyme localization. Ace- 

 tone is generally preferred, being applicable to more enzyme techniques. 

 Keep a tightly stoppered bottle of it stored in the refrigerator, ready for 

 any occasion {see also Burst one, 19^8). 



procedure: 



1. If possible chill tissue for a short tiine before immersing in ace- 

 tone. It may prevent some shrinkage artifacts. Biu fix ^vithin 10 

 minutes of death for best residts. 



2. Fix in cold acetone, 3 changes: 12 hoins each. 



3. Transfer to ether-absohue alcohol (1:1): 2 hours, refrigerator. 



